1. Field of the Invention
The invention generally relates to a liquid crystal lens and a manufacturing method thereof, and more particularly, to a three-dimensional (3D) grid controllable liquid crystal lens and a manufacturing method thereof.
2. Description of Related Art
In a common lens system, when a lens apparatus has an adjustable optical zoom function, each of the lens groups located inside the lens apparatus must generate corresponding movements to accommodate changes in the zoom ratio. In a conventional mechanical design of a miniature optical zoom lens, the mechanical design usually requires at least two driving apparatuses. That is, at least two step motors, ultra-sonic motors, piezoelectric transducers, and the like are required as the driving source.
However, implementing the zoom lens in this manner results in a bulky yet complicated structure, in contrast to a goal of product miniaturization and portability. Moreover, the relative movements of each lens group requires a position sensor and a close-loop controller to implement, which goes against a requirement of consumer products in simplicity and low price.
Moreover, besides using high cost precision driving devices as the motor sources (e.g., stepper motors, ultra-sonic motors, piezoelectric transducers) of the lens groups, the mechanical focus and zoom structures used in a common lens apparatus further employ a plurality of miniature gears, cam wheels, turbines, and the like transmission devices. Therefore, not only are the structural framework more complicated, the assembly steps made more difficult and numerous, the size more bulky and the cost more expensive, but power consumption has also exponentially increased.
Consequently, in order to alleviate the aforementioned issues, an adjustable zoom liquid crystal lens that can decrease structural complexity and minimize the bulk for the above-described lens apparatus has become increasingly important. Here, related researches are described below.
In U.S. Pat. No. 7,079,203, the disclosure proposes using a polymer network liquid crystal (PNLC) method to achieve the optical functions of the lenses. However, since the optical functions are not achieved with a single apparatus/module, consumer use is not possible due to difficulty in implementation.
Moreover, in U.S. Pat. No. 7,042,549, the disclosure proposes using a polymer dispersed liquid crystal (PDLC) process to achieve lens functions using liquid crystal droplets. However, a lens scaling modular structure is not proposed in this disclosure.
In U.S. Pat. No. 7,102,706, the disclosure proposes a method of grouping liquid crystal molecules in a PNLC. Similarly however, since the optical functions are not achieved with a single apparatus/module, consumer usage is not possible due to difficulty in implementation.
Moreover, in U.S. Pat. No. 6,898,021, the disclosure proposes a structure having a single tunable liquid crystal lens. The disclosure does not propose using PNLC to achieve lens functions, and the optical system proposed is not a multi-stage liquid crystal lens structure.
In U.S. Pat. No. 6,859,333, the disclosure proposes an apparatus utilizing electric field variations to change the light paths in a liquid crystal lens. However, since the proposed apparatus does not have a modular structure, consumer application is still limited due to implementation difficulties.
Similarly, in U.S. Pat. Nos. 5,867,238, 5,976,405, 6,002,383, 6,271,898, 6,452,650, 6,476,887, 6,497,928, 6,665,042, 6,815,016, 6,864,931, 6,897,936, 7,029,728, 7,034,907, 7,038,743 and 7,038,754, the disclosures proposed various methods of using a liquid crystal lens, and more specifically, structures including a PNLC mixture and a stop. However, these disclosures do not describe a scaling device or a modular structure.